This invention relates to delivery of respiratory gases particularly though not solely to patient interfaces for providing gases to patients requiring respiratory therapy.
In the art of respiration devices, there are well known a variety of patient interfaces which cover the nose and/or mouth of a human user in order to provide a continuous seal around the nasal and/or oral areas of the face such that gas may be provided at positive pressure for consumption by the user. The uses for such interfaces range from high altitude breathing (i.e., aviation applications) to mining and fire fighting applications, to various medical diagnostic and therapeutic applications.
One requisite of such respiratory interfaces has been that they provide an effective seal against the user""s face to prevent leakage of the gas being supplied. Commonly, in prior configurations, a good interface-to-ice seal has been attained in many instances only with considerable discomfort for the user. This problem is most crucial in those applications, especially medical applications, which require the user to wear such an interface continuously for hours or perhaps even days. In such situations, the user will not tolerate the interface for long durations and optimum therapeutic or diagnostic objectives thus will not be achieved, or will be achieved with great difficulty and considerable user discomfort.
In common with prior art designs, is an inability to seal effectively when the user""s face becomes distorted. For example, as shown in the prior art mask of FIG. 1 when the user 300 is sleeping on his or her side, one side 302 of the headgear tends to be pulled tight while the other side 304 tends to be loose. This causes the axis of the mask 306 to be twisted with respect to the axis of the head 308xe2x80x94due to the net torque from the headgearxe2x80x94resulting in leakage 310 on one side. The user 300 sleeping on his or her side may also distort the facial contours around he nasal area 312 and may lead to further leakage.
It is an object of the present invention to provide an interface which goes some way to overcoming the abovementioned disadvantages in the prior art or which will at least provide the industry with a useful choice.
It is a further object of the present invention to provide an interface which is capable of providing an effective seal against the user""s skin but which does not exert undue pressure on any part of the user""s face.
A still further object of the present invention is to provide an interface which can be produced at lower cost than current designs.
Accordingly in a first aspect the present invention consists in a device for delivering a supply of gases to a user comprising or including:
a patient interface, adapted to be in fluid communication with a supply of gases, and adapted to provide a substantially sealed flow path for said flow of gases to a user in at least a correct orientation and position on a user,
headgear adapted to attach to or around the head of a user,
a sliding connection between to said patient interface, and
wherein said sliding connection includes a sliding connection to said headgear.
Preferably said sliding connection comprises a loop adapted to slide on, through, with or adjacent said interface and adapted to slide on, through, with or adjacent said headgear.
Preferably said patient interface is a mask.
Preferably said patient interface is a nasal mask.
Preferably said patient interface is a full face mask.
Preferably said mask comprises or includes a body portion having an inlet receiving said supply of gases, and sealing means attached to or integrated with said body portion said sealing means adapted to seal against the facial contours of said user.
Preferably said sliding connection adapted to allow said headgear substantial movement with respect to said mask, while still providing compressive force on said sealing means to ensure said supply of gases is delivered to said user without significant leakage.
Preferably said sliding connection is connected to said interface at at last two points.
Preferably said loop comprises a continuous looped nylon filament.
Preferably said patient interface is a nasal cannula.
Preferably said patient interface is a mouthpiece.
Preferably said patient interface is an endotracheal tube.
In a second aspect the present invention consists in CPAP system for delivering gases to a user with a pressurised source of gases, a conduit in fluid communication with said pressurised source adapted to convey said gases, a patient interface in fluid communication with said conduit in use delivering said gases to said user, and headgear attaching said interface with said user the improvement comprising that said patient interface adapted to sliding engage with said headgear, to ensure said supply of gases is delivered to a user without significant leakage.
Preferably the improvement further comprising that said system further comprises a humidifier to variably humidify said gases.
In a third aspect the present invention consists in a device for delivering a supply of gases to a user comprising or including:
a patient interface, adapted to be in fluid communication with a supply of gases, and adapted to provide a substantially sealed flow path for said flow of gases to a user in at least a correct orientation and position on a user, and
headgear attached to the head of a user, and
at least a partial loop adapted to pass across the face of a user restraining movement of said interface with respect to said headgear.
Preferably said loop adapted to pass over and slidingly engage with said interface.
Preferably said loop adapted to pass at least partially through and slidingly engage with said interface.
Preferably said loop adapted to slidingly engage with said headgear.
In a fourth aspect the present invention consists in a mask which includes a rigid or semi rigid shell provided with a support harness for securing the mask over a user""s face, and a flexible seal; the shell being provided with inlet means for a gas supply and a mounting for an exhaust valve; the flexible seal being a push fit inside the shell and dimensioned and arranged such that when pressurized gas is supplied through the inlet means, the seal is pushed outwards against the interior of the mask and against the user""s face.
Preferably the support harness comprises a loop of low friction material which can slide freely through channels formed in the shell and relative to straps provided for securing the mask around a user""s head.
To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.
The invention consists in the foregoing and also envisages constructions of which the following gives examples.